In vitro optical quality differences between multifocal apodized diffractive intraocular lenses

Purpose: To compare the in vitro optical quality of multifocal apodized intraocular lenses (IOLs) at different focal points.

Setting: University of Valencia, Valencia, Spain.

Design: Experimental study.

Methods: The Acrysof Restor +3.0 diopter (D) multifocal IOL with 2 main foci (bifocal IOL) and the Finevision multifocal IOL with 3 main foci (trifocal IOL) were evaluated. The optical quality was quantified using the modulation transfer function (MTF) at 7 focal points and for 3.0 mm and 4.5 mm apertures. The through-focus MTF at 10 focal points of the IOLs was also recorded.

Results: For the 0.0 D and -2.5 D focal points, the bifocal IOL showed the highest MTF values for pupil sizes as well as for the -3.0 D focal point for a 3.0 mm aperture. For the -1.5 D and -3.5 D focal points, the trifocal IOL provided better MTF values, whereas for -2.0 D and -4.0 D both IOLs provided comparable results for both apertures. The through-focus MTF curves showed 3 and 2 peaks for the trifocal IOL and the bifocal IOL, respectively. With the bifocal IOL, better peak values were obtained at the 0.0 D, -2.0 D, -2.5 D, and -3.0 D focal points, while the trifocal IOL yielded better peak values at the -1.5 D and -3.5 D focal points.

Conclusion: The bifocal IOL is likely to provide a greater range of vision from distance to near than the trifocal IOL; however, at the intermediate focal point (-1.5 D), the trifocal IOL will probably yield better optical quality.

Financial disclosure: No author has a financial or proprietary interest in any material or method mentioned.